The issue of political corruption is again coming to a head. This time around, a former secretary to Mr. Koichi Kato, one-time secretary general of the Liberal Democratic Party, is suspected of tax evasion, while an ex-aide to Mr. Michihiko Kano, deputy chief of the Democratic Party of Japan, is charged with obstruction of public bidding. Opposition legislators are calling for Diet testimony by Mr. Kato.

In both cases, the secretaries allegedly took advantage of their position to make personal gains in connection with public works projects. Prime Minister Junichiro Koizumi and the heads of the two other ruling parties have agreed that coverage of the antigraft law should be broadened to include legislators' personal secretaries and relatives. The leaders of the tripartite coalition have also agreed on the need to make it a crime for politicians to meddle in public works bidding.

These are steps in the right direction. But only banning influence peddling by legislators' aides will not be enough. Strict standards of political ethics must be established. The Diet should act promptly to enact stringent measures so that the shady ties between politics and money can be effectively severed.